Oxygen producing device for woundcare

ABSTRACT

A device for the application of oxygen to promote wound healing and tissue repair. The device includes a portable oxygen generating device ( 18 ), which includes a cathode ( 10 ), an anode ( 16 ), and a phosphoric acid treated ion conducting membrane ( 14 ).

FIELD OF THE INVENTION

The present invention relates to the promotion of wound healing on skinand tissue repair. More particularly, the present invention relates tothe application of oxygen using an oxygen producing device containing aphosphoric acid treated ion conducting membrane to promote the healingof skin wounds.

BACKGROUND OF THE INVENTION

It is known that providing a supply of oxygen to a wound to or throughthe skin (e.g., ulcers, abrasions, cuts, sores, etc.) promotes healingof the wound. Oxygen therapy is used for inducing the growth of new skintissue to close and heal ischemic wounds. Topical oxygen therapy callsfor applying oxygen directly to an open wound. The oxygen dissolves intissue fluids and improves the oxygen content of the intercellularfluids. Injuries and disorders which may be treated with topical oxygeninclude osteomylelitis, tendon and cartilage repair, sprains, fractures,burns and scalds, necrotizing fasciitis, pyoderma gangrenosum,refractory ulcers, diabetic foot ulcers and decubitus ulcers (bed sores)as well as cuts, abrasions, and surgically induced wounds or incisions.

In light of the documented benefits of such oxygen therapy, there havebeen several proposed methods for providing such an oxygen supply to awound or regulating the oxygen concentration in the vicinity of a woundwhile also preventing contamination of the oxygen supply from the wound.Prior art teaches the application of topical hyperbaric oxygen byplacing the entire affected limb of a person in a sealed chamber thatfeatures controlled pressure sealing and automatic oxygen regulationcontrol. Not only are such oxgygen chambers expensive and difficult tosterilize, however, they are also cumbersome in that the chamber must behooked up to an external oxygen tank, limiting the patient's mobility.In addition, because the entire limb is placed in a chamber or bag,large areas of skin may be unnecessarily subjected to high levels ofoxygen. Such high levels of oxygen present risks of vasoconstriction,toxicity and tissue destruction. U.S. Pat. No. 4,328,799 to LoPianodescribes such a system in which a recumbent patient is connected to agas chamber attached to an oxygen supply.

U.S. Pat. Nos. 5,578,022 and 5,788,682 describe systems in which oxygenproducing devices are incorporated into a patch or bandage which isplaced directly over a wound. Both these patents describe devices inwhich oxygen is produced electrochemically and transported across an ionconductive membrane. In such membranes, water typically provides ahydrogen bonding network and enables the rapid movement of protonsthrough the membrane necessary for oxygen production in such a system.Water, however, has a relatively high vapor pressure and will evaporate.As water in the membrane evaporates, the membrane loses its ability toeffectively conduct ions. Thus, over the course of several days,membranes used in such devices tend to lose their ability to transportoxygen. Attempting to keep the membrane hydrated can result incomplications. For example, the inclusion of a water source to keep themembrane moist can make the device cumbersome, mitigating one of the keybenefits of such a device. In addition, water presents a potentialbreeding ground for microbes. This is highly undesirable in such anoxygen generating device, which is often placed on or near open woundsthat are susceptible to microbial infection.

Therefore, a need exists for a convenient and inexpensive means ofmaintaining the ionic conductivity of the membrane in suchelectrochemical oxygen producing devices over an extended period oftime.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a device for supplying oxygen for treatment of wounds toan ambulatory patient is provided, the device including a wound dressingadapted for receipt over a skin wound treatable with oxygen including aphosphoric acid treated ion conducting membrane, a portable oxygengenerating device remote from said wound dressing for supplying oxygento the skin wound, and a conduit fluidly connecting said oxygengenerating device with said wound dressing.

In a second aspect, a portable, self-contained device for generating andsupplying oxygen for treatment of wounds to an ambulatory patient isprovided, the device including a phosphoric acid treated ion conductingmembrane.

In a third aspect, a method for treating wounds using an electrochemicalcell is provided, the method including the steps of bringing ambient airinto contact with a porous cathode mounted in a housing, reducing oxygenpresent in the air to neutral species at the cathode, diffusing theneutral species through a phosphoric acid treated ion conductingmembrane to a porous anode mounted in the housing, oxidizing the neutralspecies to oxygen at the anode, and administering a supply of oxygen toa skin wound.

The present invention relates to a process to make oxygen producingdevices for wound care application. The present invention overcomes someof the inherent problems in the construction and operation of theportable, self-contained devices for the topical application of oxygento promote wound healing described in U.S. Pat. Nos. 5,578,022 and5,788,682. These concerns include:

An oxygen generating device for wound healing application must be thinand flexible. Thick end plates (for electrical connection and air andoxygen delivery) often used in such devices do not fulfill thisrequirement.

Membranes made from presently available ironically conducting polymersdry out when exposed to ambient conditions. When dry, such membranesshow high ionic resistance resulting in device failure.

For wound healing application, the oxygen generating device is securedwith adhesive tapes and is exposed to several impurities, which poisonthe catalyst for oxygen reduction and/or generation.

Many wound locations, e.g., foot, heal, lower ankle etc., call fordevices that are ultra thin, so that they will not interfere with shoesand such outerwear that are part of an ambulatory patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, a preferred embodiment of which will be described in detail inthis specification and illustrated in the accompanying drawings whichform a part hereof.

FIG. 1 is a schematic representation of a side view of an oxygenproducing patch in accordance with the present invention.

FIG. 2 is a schematic representation of a plan view of an oxygenproducing patch incorporating a plurality of batteries in accordancewith the present invention.

FIG. 3 is a cutaway side view of an oxygen producing patch with tubingin accordance with one embodiment of the invention deployed on apatient.

FIG. 4 is a schematic diagram of a membrane electrode assembly (MEA) foruse in the oxygen generating device of shown in FIG. 2.

FIG. 5 is a graph showing life test data with patch assemblies accordingto the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings wherein the showings are for purposes ofillustrating a preferred embodiment and not for purposes of limiting thesame, the figures show a new approach for generating oxygen to healwounds.

With reference to FIG. 1, a side view of an oxygen producing device andpatch assembly in accordance with one aspect of the present invention isshown. The device includes a porous cathode 10, an ion conductingmembrane 14 and a porous anode 16 inside a housing 18. The cathode isexposed to the atmosphere, such as through a vent 20, and the anode isexposed to or in communication with the skin wound 36. Attached to aperimeter of an underside of the housing 18 is an adhesive strip 22,which completely encircles the base and is used to secure the device tothe patients skin 24 or a bandage 26 around the wound. The adhesivestrip 22 does not touch the wound, but serves to cause the housing ofthe device to stand off a slight distance from the wound itself, suchthat a cavity 28 is formed between a bottom of the housing 30 and thewound. This cavity 28 becomes filled with gaseous oxygen emitted fromthe interior of the housing through holes 32 on the bottom of thehousing 30. Alternately, instead of holes 32, the bottom of the housing30 may be formed of a material permeable to oxygen. The adhesive stripmay be permeable to oxygen gas to prevent undue gas pressure frombuilding up in the cavity 28. This permeability may be obtained byhaving formed valves or capillary holes through the adhesive layer (notshown) but preferably will be obtained by having the adhesive materialitself be somewhat porous, since the formed passageways may have agreater tendency to allow contaminants to enter cavity 28 when thedevice is not operating. The oxygen pressure in the cavity 28 will varydepending on the permeability of the housing bottom, the number ofvalves and the identity of the adhesive material, and the rate of oxygenproduction. However, the pressure will preferably not exceed about 20-30mm Hg to prevent vasoconstriction.

Adhesive is depicted at 22 for affixing the patch over a skin wound suchthat oxygen cannot flow readily out of the treatment area. As stated,the patch will generally have one or more one-way valves or smallcapillary holes to permit outflow of air. The patch may be incorporatedinto, include, or be deployed on top off or underneath one or morebandage layers 34. The bandage itself may have multiple layers topromote patient comfort and healing, including but not limited to layersof cotton gauze, polyethylene oxide-water polymer, as well as layer(s)containing topical ointments and other medicinals including antibiotics,antiseptics, growth factors and living cells. Preferably, the bandage isocclusive on all sides and offers anti-microbial control withoutantibiotics or antiseptics, although these can still be used for addedprotection.

Positioned between the anode 16 and the cathode 10 is an ion conductingmembrane 14. At electrode 10 a cathodic reaction occurs to combine theambient oxygen from the air into water, in which it is present asreduced oxygen. The voltage differential created by electrodes 10 and 16a drives the species across the membrane 14, which is specific topassage of that species. At anode 16, an anodic reaction occurs toconvert the species to release the reduced oxygen as gaseous oxygen ontothe wound site.

With attention now directed to FIG. 2, single patch 48 can be equippedwith several sealed zinc/air batteries 50. This will enable the patientto apply oxygen intermittently as is usually the case with presenttreatments. Each battery may be manufactured according to apredetermined life span. For example, each of the batteries can be setto last for 1 hour, 2 hours, 4 hours, more time or less time.Differently sized batteries can be incorporated into a single patch sothe same patch can be maintained in place for a period of time beforethe dressings are removed for cleansing of the wound. This permitsdifferently timed dosages of oxygen to be applied to a wound. Forexample, a one hour therapy can take place on day 1, followed by a 2hour therapy on day 2, and so on. Each battery includes a peel offsticker. When the sticker is removed, the zinc/air battery or other airdriven battery is exposed to the air and begins operating. The oxygengenerating portion, including a cathode, anode, and ion conductingmembrane as described above, is depicted at 54.

In the alternative to having multiple batteries, a single battery havingan electronic timing device may be included for a seven day or longeroxygen therapy treatment. Because of its monolithic construction,patches can, in principle, be manufactured in any size or shape, evenincluding a transparent plastic window directly above the wound tovisually monitor the healing progress (neovascularization) withouthaving to remove the patch. FIG. 2 shows such a viewing or inspectionwindow at 58. In use, the wound would be located below the window. Asshown in FIG. 1, the patch can be affixed to the skin with a simpleadhesive layer around the perimeter. The patch may be made in manyshapes such as gloves, socks, sleeves, etc. and may be cut to size.

With reference to FIG. 3, an oxygen producing device and patch assembly80 according to a second embodiment of the invention is shown generallyand includes a dressing or bandage 82 to be placed over a wound, aportable oxygen producing device 84 as described above for supplyingoxygen to the wound, and a conduit such as a flexible tubing 86 fluidlyconnecting the oxygen producing device with the bandage 82 and theunderlying wound. The flexible tubing may include a Luer type connectionor similar type. The tubing 86 is preferably made from a polymericmaterial suitable for use in hospital applications. Suitable materialsfor use in the tubing include, but are not limited to, silicone,polyethylene, polypropylene, polyurethane and various otherthermoplastics.

Oxygen is produced at the oxygen producing device 84 via anelectrochemical reaction. The oxygen then travels through the flexibletubing 86 to the bandage covered wound. Depending on the type of woundand the dressing used to cover it, the tubing can contact the dressingin various ways. For example, the end of the tubing 86 may be placeddirectly above the wound and under fully occlusive dressings 82, therebymaking an ordinary bandage “oxygen enriched”. Any type of bandage may beused, including those described above.

In other applications, the device is capable of treating venous legulcers where the patient must wear woven four part compression dressingsto control swelling and edema. The remote oxygen producing device 84with a tubing 86 can be placed on the top layer of the compressiondressing, thus avoiding compressing the device tightly against the legas would be necessary with prior art devices. The tubing 86 may be wovenbetween the four individual layers of the compression dressing toconform directly to the leg without unduly compressing the oxygengenerator, batteries and hardware comprising the oxygen producing device84 against fragile skin surrounding the wound. Positioning the device ontop of the compression dressing also provides the further advantage ofassuring unrestricted delivery of oxygen from atmospheric air to thewound, rather than relying on atmospheric diffusion through thedressing.

The remote device can be positioned on the patient wherever convenientand comfortable. Patients with wounds on the bottom of their feet, forexample, can wear a thin bandage, add the soft tubing and attach thedevice away from the wound on the ankle or leg. The patient is thus ableto wear a shoe while being treated with oxygen without having size andcomfort restraints created by the prior art. For patients with wounds tothe sacrum heel, back or other pressure points, the device can beremotely placed away from the wound and pressure point for optimumcomfort. Then, the relatively soft tubing can be directed to the woundsite.

While microbes from a wound site may contaminate a bandage or dressingplaced over it, the use of the remote device with a disposable, steriletubing prevents microbial reflux from reaching the device. The tubingserves as a microbial barrier to the device. When in operation, thetubing provides positive gas pressure from the device to the wound andis separated by a sufficient distance to prevent reflux contamination ofthe device. Optionally, a microbial biofilm interrupting mechanism, suchas a semi-permeable membrane may be implemented with the device withinor at either end of the tubing as a further safeguard.

For in vivo uses, the end of the tubing 86 can be implanted to the sitewhere treatment is desired. The implanted end of the tubing 86 may beperforated with multiple holes or made of material that would allowoxygen to diffuse through the tubing wall into ischemic tissue or thebloodstream. In addition, a syringe can be attached to the end of thetubing to facilitate the introduction of oxygen subdermally. Sitespecific oxygen delivery to promote localized angiogenesis or ischemicreperfusion and elevated metabolism is beneficial for orthopedic andorgan repair as well as tissue, bone, tendon, and cartilageregeneration. Localized oxygenation of tissue and tumors for improvedradiological oncology applications may benefit with the present device.

Thus, the present device may be considered a universal remote supply ofoxygen in that it can be used with a wide variety of bandages ordressings already on the market. Additional types of dressings withwhich the present invention may be used include fully occlusive thinfilm dressings, hydrocolloid dressings, alginate dressings,antimicrobial dressings, biosynthetic dressings, collagen dressings,foam dressings, composite dressings, hydrogel dressings, warm updressings, and transparent dressings. This universal property isprovided by the tubing delivery pathway of oxygen, which is not known inthe prior art.

With reference to FIG. 4, the oxygen producing device of the presentinvention suitable for use in any of the above described embodiments canbe described generally as comprising a membrane electrode assembly (MEA)100 for the electrochemical production of oxygen from air or water. Anion conducting membrane 102 is positioned between two electrodes 104,106, which in turn are connected to a power source 108, such as abattery, capable of passing a current across the electrodes.

As shown in FIG. 4, oxygen in ambient air is reduced to water at aninterface region 110 between the cathode 104 held at a reducingpotential and the membrane 102 using the protons supplied by themembrane according to a reaction as described below. The product wateris moved through the membrane 102 to the anode 106 held at an anodicpotential, which oxidizes the water back to oxygen while releasingprotons at an interface region 112 between the anode and the membrane.The protons move through the membrane to the cathode 104 to makepossible continued reduction of oxygen from air. Atmospheric nitrogenand carbon dioxide are electrochemically inert under the reactionconditions required for oxygen reduction and, thus, are effectivelyrejected at the cathode. The reduction product of oxygen alone movesthrough the membrane, resulting in near 100% pure oxygen on the anode.This oxygen is then directed to the tubing for delivery to a wound site.

The ion conducting membrane may be any of a number of known ionconducting membranes which are capable of conducting protons and otherionic species. Suitable membranes include various perfluoronated ionomermembranes that include a poly(tetrafluoroethylene) backbone andregularly spaced perfluoronated polyether side chains terminating instrongly hydrophilic acid groups. A preferred group of membranessuitable for use in the present invention include those containingsulfonic acid terminating groups on the side chains and available underthe trademark Nafion® from E.I. Dupont Co. Nafion® is a perfluorinatedpolymer that contains small proportions of sulfonic or carboxylic ionicfunctional groups. Its general chemical structure can be seen below,where X is either a sulfonic or carboxylic functional group and M iseither a metal cation in the neutralized form or an H⁺ in the acid form.Other suitable membranes include partially fluorinated membranematerials and those based on hydrocarbon polymer backbones.

The following reaction mechanisms may be used in the present inventionfor the production of oxygen including:

At the cathode: O₂+4H⁺+4e−→2H₂O

At the anode: 2H₂O→O₂+4H⁺+4e⁻

with the net reaction being the depletion of a gaseous oxygen (fromambient air) on one side of the membrane and an increase of the oxygenconcentration on the other side.

The electrodes used in the membrane electrode assembly can be in theform of a mesh or a thin coating on the opposite surfaces of themembrane. They can be made of any materials which are electricallyconductive and which will catalyze the reduction of gaseous oxygen intowater, provide a voltage differential across the membrane to move theoxygen containing species and catalyze the oxidation of the productwater to release oxygen. Suitable electrode materials include, but arenot limited to, platinum, iridium, rhodium ruthenium as well as theiralloys and oxides in a pure finely divided form or as supportedcatalysts.

In one embodiment of the present invention, Nafion® membrane is treatedor imbibed with 85-100% Phosphoric acid. In Nafion®, water normallyprovides the hydrogen bonding network and enables the rapid movement ofprotons through the polymer (and hence the high ionic conductivity).However, when left under ambient conditions, Nafion® loses water to thesurroundings (due to the relatively high vapor pressure of water), whichresults in the loss of ionic conductivity. Phosphoric acid can alsoprovide a hydrogen bonding network similar to that of water, but unlikewater, has a very low vapor pressure—at room temperature the vaporpressure of phosphoric acid is so low that it can be considered zero. Itis also hygroscopic to a degree, such that it may absorb water from theatmosphere. This combination of properties makes it possible to replacemost of the water in Nafion® with phosphoric acid under appropriateconditions. Nafion®, thus treated with phosphoric acid continues toprovide adequate ionic conductivity when exposed to ambient conditionsfor extended periods of time (several months). The effect of this can beseen in FIG. 5, which shows that such oxygen producing devices utilizedwith bandages in the treatment of wounds maintained a steady voltage(and hence continued to generate oxygen) for up to 500 days at aconstant applied current of 15 mA. The intrinsic conductivity of aphosphoric acid imbibed Nafion® is much lower than that of water imbibedNafion® at room temperature. For low current density applications suchas the present usage, however, this decreased conductance is quiteacceptable.

The electrochemical process is driven by the battery 50. The battery maycomprise a plurality of sealed zinc/air batteries. This enables thepatient to apply oxygen intermittently, as is usually the case withpresent treatments. Each battery may be manufactured according to apredetermined life span. For example, each of the batteries can be setto last for 1 hour, 2 hours, 4 hours, or other time periods. Differentsized batteries may be incorporated into a single oxygen producingdevice. This permits differently timed dosages of oxygen to be appliedto a wound. Each battery may include a peel off sticker that, whenremoved, exposes the battery to air and begins operating. Reversing thepolarity of the battery will reverse the process so that a very lowlevel of oxygen (as low as about 0% oxygen concentration) is supplied tothe wound, thereby modulating the level of oxygen in the wound treatmentarea. The modulation of the level of oxygen will control the rate ofwound healing by increasing or decreasing the oxygen tension in thetissues that stimulate healing. Other types of power sources includebatteries, fuel cells, photovoltaic cells and supercapacitors incombination with one or more of the above power sources.

The conventional method of making a membrane electrode assembly that iscapable of accomplishing the above goal consists of bonding a Pt/Celectrode and a Pt black electrode to either side of a Nafion® 117 (orsimilar) membrane. The electrical connections from the electrodes to thevoltage source are normally provided through conducting end plates thatare normally made of thick graphite or metallic material. To reduceweight and improve mobility of the device, a thin (e.g., 1-5 mil),electronically conducting and electrochemically inert wire is placed inbetween the membrane and electrode during the bonding process, therebymaking the electrical connection an integral part of the membraneelectrode assembly. Examples of such wires include: gold, Pt, gold or Ptplated or deposited Ta, and similar materials.

In addition, a catalyst is used to improve the electrochemicalproduction of oxygen in the above reactions. The addition of a catalystin one or both electrodes aids in overcoming the kinetic reactionbarriers. Preferably, a Pt—Ru, Pt—Ir, or similar noble metal alloycatalysts that is poison resistant is used to coat the electrodes. Theuse of such poison resistant catalysts will prevent impuritiesintroduced from the adhesive and other components of the device fromreducing the catalyst activity and deactivating the device. Suitablenon-limiting examples of anode catalysts include Pt—Ir, Pt—Sn, andternary combinations thereof. Suitable non-limiting examples of cathodecatalysts include Pt—Ru/C, Pt—Sn, Pt—Ir, Pt—C, and ternary combinationsthereof. A preferred catalyst is Pt—Ir.

An electronic PC board or controller (not shown) may be incorporatedinto the device and can contain an on-off switch and a currentmonitoring port. The amount of oxygen generated by the device can bevaried by changing the voltage applied across the electrodes. Typically,the device will produce between about 1 and about 50 ml oxygen/hr, morepreferably between about 1 and about 10 ml/hr.

The device and design as taught in this application has clear advantageover a conventional means of delivering oxygen, i.e., a tank filled withoxygen placed in proximity to the wound. For example, for a treatmentregime of 3 weeks, the amount of oxygen required could range anywherebetween 2100 cc to 6,300 cc. Typical weight efficiency of high pressurestorage containers are 2%. To store 2.1 liters of oxygen, the totalweight of the container alone will be ˜300 grams. The weight of theregulator system for such high pressure will add additional weight. Tostore 2 liters of oxygen in a 50 ml volume, we have to pressurize thecontainer to 40 atmospheres. It is clear therefore, from weight, volumeand safety standpoints, high pressure oxygen storage is not the best wayto practice oxygen delivery bandages for ambulatory patients.

In addition to the reduced weight, the oxygen producing device of thepresent invention allows precise control of the amount of oxygen thatreaches a wound. By setting a low flow rate, the wound is discouragedfrom drying out, allowing for a moist wound healing process, which isthe standard preferred method. This controlled, slow oxygen gas flowfrom the device can not be easily replicated using compressed oxygencylinders. The lowest flow rates from commercially available pressureregulators fitted to compressed gas cylinders flow far too much gas tobe used in moist wound healing applications or in vivo uses. The bulkweight and attendant fire hazard associated with compressed cylindersalso make such a system unsuitable for wound healing or internalmedicine.

The methods used for generating and depleting oxygen are preferablyelectrochemical in nature, although nonelectrochemical methods may beused to administer the oxygen to treatment area. For example, chemicallyor thermally induced reactions that could release or absorb oxygen in acontrolled fashion may be employed.

The invention has been described with reference to various preferredembodiments. Obviously, modifications and alteration will occur toothers upon a reading and understanding of this specification. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentthereof.

1. A device for supplying oxygen to a patient for treatment of a woundor condition comprising: a wound dressing adapted for receipt over awound or injury treatable with oxygen; a portable oxygen generatingdevice remote from said wound dressing for supplying oxygen to the skinwound, said device comprising an anode, a cathode, a power source and aphosphoric acid treated ion conducting membrane for electrochemicallyproducing oxygen; a conduit fluidly connecting said oxygen generatingdevice with said wound dressing.
 2. A device for supplying oxygenaccording to claim 1, wherein said conduit is a flexible tubing.
 3. Adevice for supplying oxygen according to claim 2, wherein said wounddressing is a woven four part compression dressing for treating venousulcers.
 4. A device for supplying oxygen according to claim 2, whereinsaid tubing is woven between the individual layers of the compressiondressing.
 5. A device for supplying oxygen according to claim 2, whereinsaid oxygen is delivered subdermally.
 6. A device for supplying oxygenaccording to claim 2, further comprising a syringe fluidly connected toan end of said tubing for subdermal delivery of oxygen.
 7. A device forsupplying oxygen according to claim 2, further including a semipermeablemembrane for preventing microbial reflux into the oxygen producingdevice.
 8. A device for supplying oxygen according to claim 2, whereinthe production of oxygen occurs according to a four electron process. 9.A device for supplying oxygen according to claim 2, wherein said ionconducting membrane is a perfluorinated ionomeric membrane.
 10. A devicefor supplying oxygen according to claim 2, wherein said power sourcewhich applies a current across said cathode and anode.
 11. A device forsupplying oxygen according to claim 2, further including a catalyst inat least one of said anode and cathode.
 12. A device for supplyingoxygen according to claim 11, wherein said catalyst comprises Pt—Ir. 13.A device for supplying oxygen according to claim 2, wherein said devicegenerates between about 1 to about 50 ml oxygen/hr under standardtemperature and pressure.
 14. A device for supplying oxygen according toclaim 2, wherein said device is capable of producing oxygen for severalweeks without the addition of water to the device.
 15. A device forsupplying oxygen according to claim 2, wherein said tubing is perforatedwith a plurality of holes to for in vivo treatment.
 16. A device forsupplying oxygen according to claim 2, wherein said oxygen generatingdevice is mounted on a patient.
 17. A device for supplying oxygen to apatient for treatment of a wound or condition comprising: a wounddressing adapted for receipt over a wound or injury treatable withoxygen; and a portable oxygen generating device for supplying oxygen tothe skin wound, said device comprising an anode, a cathode, a powersource and a phosphoric acid treated ion conducting membrane forelectrochemically producing oxygen.
 18. A device for supplying oxygenaccording to claim 17, wherein said device generates between about 1 toabout 10 ml oxygen/hr under standard temperature and pressure.
 19. Amethod for treating wounds or conditions using an electrochemical cell,comprising the steps of: bringing ambient air into contact with a porouscathode mounted in a housing; reducing oxygen present in the air toneutral species at the cathode; diffusing the neutral species through aion conducting membrane to a phosphoric acid treated porous anodemounted in the housing; oxidizing the neutral species to oxygen at theanode; and administering a supply of oxygen from the anode to a dressingand an underlying wound or injury.
 20. A device for supplying oxygen toa patient for treatment of a wound or condition comprising: a wounddressing adapted for receipt over a wound or injury treatable withoxygen; and a portable oxygen generating device for supplying oxygen tothe skin wound, said device comprising an anode, a cathode, a powersource, an ion conducting membrane for electrochemically producingoxygen, and at least one catalyst associated with at least one of saidanode and said cathode.
 21. A device according to claim 20, wherein saidcatalyst is associated with said anode and is selected from the groupconsisting of Pt—Ir, Pt—Sn, and ternary combinations thereof.
 22. Adevice according to claim 20, wherein said catalyst is associated withsaid cathode and is selected from the group consisting of Pt—Ir, Pt—Sn,Pt—Ru/C, Pt—C, and ternary combinations thereof.